Method of selecting a bituminous emulsion based on its coalescence

Abstract

A method of selecting a bituminous emulsion with enhanced performance for paving is provided. This method includes selecting polymer modified bitumen with a penetration value of about 25 to 450 dmm at 25° C. and selecting one or more emulsifiers comprised of at least about 5% by mass of a cationic nitrogenous compound selected from compounds having a carbonyl carbon atom bonded to a nitrogen atom, compounds having a carbon atom double bonded to a nitrogen atom, or combinations thereof based on the total mass of the selected emulsifier. Each selected emulsifier is reacted with a carboxylic acid to create one or more carboxylate salts. Each carboxylate salt created from a different proposed emulsifier separately is mixed with the bitumen to form one or more proposed bituminous emulsions. The coalescence of each proposed bituminous emulsion is measured using a rheology test, and a bituminous emulsion of the composition described above is chosen for paving a surface based on its coalescence properties.

1. A method of selecting a bituminous emulsion with enhanced performance, comprising:
 (a) selecting at least one proposed emulsifier comprised of at least about 5% by mass of a cationic nitrogenous compound selected from the group consisting of compounds having a carbonyl carbon atom bonded to a nitrogen atom, compounds having a carbon atom double bonded to a nitrogen atom, and combinations thereof based on the total mass of said proposed emulsifier; 
 (b) reacting said proposed emulsifier with a carboxylic acid to create at least one proposed carboxylate salt; 
 (c) mixing bitumen and said proposed carboxylate salt to form at least one proposed bituminous emulsion; 
 (d) applying said proposed bituminous emulsion to a surface; 
 (e) measuring coalescence of said proposed bituminous emulsion; and 
 (f) selecting a bituminous emulsion for paving a surface after said coalescence measuring step and choosing said bituminous emulsion based on said coalescence measurement of said proposed bituminous emulsion. 
 
     
     
       2. The method of  claim 1  wherein said bitumen has a penetration value of about 25 to 450 dmm at 25° C. 
     
     
       3. The method of  claim 1  wherein said proposed bituminous emulsion has a residue of about 35 to 85% based on the weight of the emulsion. 
     
     
       4. The method of  claim 1  wherein said bitumen is polymer modified. 
     
     
       5. The method of  claim 1  wherein said cationic nitrogenous compound is selected from the group consisting of imidoamines, imines, amidoamines, amides, imadazoles, and combinations thereof. 
     
     
       6. The method of  claim 1  wherein coalescence is measured using is a rheology test. 
     
     
       7. The method of  claim 1  wherein coalescence is directly measured. 
     
     
       8. The method of  claim 7  wherein coalescence is measured using a demulsibility test. 
     
     
       9. The method of  claim 7  wherein coalescence is measured using a sand-break index test. 
     
     
       10. The method of  claim 1  wherein coalescence is measured within about 48 hours of when said bituminous emulsion is applied to said surface. 
     
     
       11. The method of  claim 1  wherein coalescence is measured within about 24 hours of when said bituminous emulsion is applied to said surface. 
     
     
       12. The method of  claim 1  wherein coalescence is measured within about 12 hours of when said bituminous emulsion is applied to said surface. 
     
     
       13. The method of  claim 1  wherein said proposed emulsifier is comprised of at least about 10% by mass of said cationic nitrogenous compound based on the total mass of said emulsifier. 
     
     
       14. The method of  claim 1  wherein said proposed emulsifier is comprised of at least about 20% by mass of said cationic nitrogenous compound based on the total mass of said emulsifier. 
     
     
       15. The method of  claim 1 , further comprising:
 reformulating said proposed bituminous emulsion by repeating steps (a)–(e) if the coalescence of said proposed bituminous emulsion is undesirable, before performing step (f). 
 
     
     
       16. The method of  claim 15  wherein said reformulating step includes increasing the amount of said cationic nitrogenous compound in said proposed emulsifier. 
     
     
       17. The method of  claim 15  wherein said reformulating step includes selecting a different carboxylic acid. 
     
     
       18. The method of  claim 6  wherein said rheology test is selected from the group consisting of an abrasion test, a tangential sheer test, an impact test, a tensile test, a torque test, a compression test, an adhesion test and a binder viscosity test. 
     
     
       19. The method of  claim 18  wherein said rheology test is a sweep test. 
     
     
       20. The method of  claim 18  wherein said rheology test is a vialit test. 
     
     
       21. The method of  claim 18  wherein said rheology test is a tensile test. 
     
     
       22. The method of  claim 1  wherein said carboxylic acid is selected from the group consisting of mono, di- and tricarboxylic acids and combinations thereof. 
     
     
       23. The method of  claim 1  wherein said carboxylic acid is selected from the group consisting of acetic acid, formic acid, propionic acid and combinations thereof. 
     
     
       24. The method of  claim 1  wherein said carboxylic acid is acetic acid. 
     
     
       25. The method of  claim 19  wherein said selected bituminous emulsion has a mass loss from said sweep test that is reduced by at least about 10% at 1 hour compared with a bituminous emulsion hydrochloride salt control. 
     
     
       26. The method of  claim 19  wherein said selected bituminous emulsion has a mass loss from said sweep test that is reduced by at least about 20% at 1 hour compared with a bituminous emulsion hydrochloride salt control. 
     
     
       27. The method of  claim 19  wherein said selected bituminous emulsion has a mass loss from said sweep test that is reduced by at least about 30% at 1 hour compared with a bituminous emulsion hydrochloride salt control. 
     
     
       28. A method of selecting a bituminous emulsion with enhanced performance, comprising:
 (a) selecting at least one proposed emulsifier comprised of at least about 5% by mass of a cationic nitrogenous compound selected from the group consisting of compounds having a carbonyl carbon atom bonded to a nitrogen atom, compounds having a carbon atom double bonded to a nitrogen atom, and combinations thereof based on the total mass of said proposed emulsifier; 
 (b) reacting said proposed emulsifier with a carboxylic acid selected from the group consisting of acetic acid, formic acid, propionic acid and combinations thereof to create at least one proposed carboxylate salt; 
 (c) mixing bitumen and said proposed carboxylate salt to form at least one proposed bituminous emulsion; 
 (d) applying said proposed bituminous emulsion to a surface; 
 (e) measuring coalescence of said proposed bituminous emulsion using a rheology test within about 48 hours of when said proposed bituminous emulsion is applied to said surface; and 
 (f) selecting a bituminous emulsion for paving a surface after said coalescence measuring step and choosing said bituminous emulsion based on said coalescence measurement of said proposed bituminous emulsion.